Various neck traction systems are found in the prior art. U.S. Patent Publication U.S. 2007/0055306 A1 to Han discloses a traction apparatus for the cervical vertebrae and shows a neck traction unit wherein the user has manual longitudinal adjustment and manual elevational adjustment. Han '306 utilizes manual screw drive controls to elevate the head and manual screw drive control to elongate and provide neck traction. These manual screw controls may be replaced by motor driven screw drives.
U.S. Patent Publication US 2007/0118991 A1 to Nakayama discloses a pillow with internal elevational springs. Nakayama '991 does not disclose a traction system which transfers downward head weight to a longitudinal extension for neck traction.
U.S. Pat. No. 5,067,483 A to Freed discloses a cervical traction device and shows an angled traction unit with a powered, down-angle extension element for the shoulder pads. Freed '483 does not utilize the weight of the head of the user to develop neck traction.
Other traction systems are shown in: U.S. Patent Publication US 2001/0029345 A1 to Anderson for Cervical/Upper Thoracic Relaxer (traction stand); U.S. Pat. No. 6,875,189 B1 to Nelson for Cervical Traction Device; U.S. Pat. No. 6,217,538 B1 to Anderson for Cervical/Upper Thoracic Relaxer (traction stand); U.S. Pat. No. 4,832,007 A to Davis for Traction Pillow and Method shows a pillow with air release channels; U.S. Pat. No. 4,784,122 A to Graham for Portable Cervical Traction Device using Constant Force Springs; U.S. Pat. No. 4,593,684 A to Graham for Occipital Support for Cervical Traction; U.S. Pat. No. 4,166,459 A to Nightingale for Cervical Traction Unit; U.S. Pat. No. 3,648,308 A to Greenawalt for Elevated Traction Pillow; U.S. Design Pat. No. D 431,080 S to Anderson for Combined Cervical and Upper Thoracic Relaxer shows a traction stand; U.S. Design Pat. No. D 330,083 S to Nightingale for Cervical Traction Unit; U.S. Design Pat. No. D 272,467 S to Nightingale for Cervical Traction Unit; U.S. Design Pat. No. D 229,359 S to Nightingale Cervical Traction Halter; and Japanese Patent Publication JP 3374272 B2 to Matsuoka.